I checked motor mounts but I will recheck them again. We cranked down the suspension at the track with straps really low so it was almost rigid so I will check the frame for any cracks as well. I used an oem flywheel key. When it was shearing them after the rebuild I ordered like 4 of them. I had an oddball retaining nut on and now I have the oem nut with red loctite, I forgot loctite when I installed the flywheel last time.